Bone plate and method for using bone plate

ABSTRACT

Various embodiments of the present invention relate to a bone plate apparatus and methods for using the bone plate apparatus. More particularly, in one embodiment the bone plate apparatus and/or method may be used in connection with a laminoplasty procedure.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. 119(e) of U.S. Provisional Application Ser. No. 60/512,653, filed Oct. 20, 2003

FIELD OF THE INVENTION

Various embodiments of the present invention relate to a bone plate apparatus and methods for using the bone plate apparatus.

More particularly, in one embodiment the bone plate apparatus and/or method may be used in connection with a laminoplasty procedure.

BACKGROUND OF THE INVENTION

Examples of various patent documents in the laminoplasty area include the following:

U.S. Patent Publication No. 20040030388 in the name of Null et al. relates to laminoplasty devices and methods. More particularly, laminoplasty plates are engageable to at least one portion of a divided lamina to maintain a desired spacing relative to the spinal canal. The laminoplasty plates include a spacer portion having a first end and a second end that spans a gap formed by at least one of a divided lamina portion. The laminoplasty plates can include a lamina engagement portion at one end for engagement with the divided lamina portion.

U.S. Pat. No. 6,080,157 to Cathro et al. relates to a device to stabilize the lamina. More particularly, a device for dynamically stabilizing the lamina after a laminoplasty includes a spacer which is shaped to engage between the severed edges of the lamina. The device also includes a retainer attached to the spacer which is adapted to maintain the spacer in an operative position. A method of dynamically stabilizing the lamina after a laminoplasty is also provided, which includes the steps of positioning the spacer between the severed edges of the lamina, and positioning the retainer to maintain the spacer in the operative position.

U.S. Patent Publication No. 20030125738 in the name of Khanna relates to a laminoplasty with laminar stabilization method and system. More particularly, fixation devices and methods for stabilization of the lamina after laminoplasty are described. The device comprises a plate with several holes that receive bone fasteners. The plate is curved at the ends to contour to the vertebral structure and has appendages to engage the displaced lamina in a fixed position. Alternatively, the plate has a bone fusion spacer in the middle to engage and fuse the lamina in the displaced position. Several methods of dynamically stabilizing the lamina after either the open door, double door or expansive laminoplasty technique are provided.

U.S. Pat. No. 6,712,852 to Chung et al. relates to a laminoplasty cage. More particularly, a medical implant device for use in spinal surgery, and more preferably for use in laminoplasty surgery is provided. The implant is a cage-like member having a generally hollow, elongate body with open ends. The implant is formed from a generally hollow, elongate body having four sides: opposed cephalad and caudal sides, and opposed posterior and anterior sides adjacent to the cephalad and caudal sides. The four sides extend along a longitudinal axis, and define an inner lumen extending between opposed first and second open ends.

U.S. Pat. No. 6,635,087 to Angelucci et al. relates to laminoplasty implants and methods of use. More particularly, implants for use in the spinal column are disclosed. The implants comprise a bone allograft coupled with a non-allogenic plate. The plate has ends that fasten to opposing spine segments, and an intermediate portion that engages the allograft using deformable fingers, or with a hollow portion sized to receive and hold part of the allograft, or with fixed tabs. Methods of using the implants are also disclosed.

U.S. Patent Publication No. 20030045935 in the name of Angelucci et al. relates to laminoplasty implants and methods of use. More particularly, implants for maintaining a distance between cut spinal bones are disclosed. The implants are made of metal, polymer or bone allograft, and have ends angled with respect to each other to conform to the cut bone ends. The implants have hollow regions for packing osteogenic material. The implant ends have surface projections to reduce slippage. Implants made of bone allograft also have ends made of demineralized bone to speed fusion between spine and implant. Methods of using the implants are also disclosed.

U.S. Patent Publication No. 20020120335 in the name of Angelucci et al. relates to laminoplasty implants and methods of use. More particularly, implants for maintaining a distance between cut spinal bones are disclosed. The implants are made of metal, polymer or bone allograft having ends configured to conform to the cut bone ends. The implants have hollow regions for packing osteogenic material. The implant ends have surface projections to reduce slippage. Implants made of bone allograft also have spine contacting ends made of demineralized bone to speed fusion of spine and implant; they may also have bone flaps to fix the implant to the spine. Methods of using the implants are also disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of one embodiment of a bone plate apparatus according to the present invention;

FIGS. 2A and 2B show exploded perspective views of the bone plate apparatus of FIG. 1 (FIG. 2A shows the bone plate apparatus from one angle and FIG. 2B shows the bone plate apparatus from another angle);

FIGS. 3A, 3B and 3C show, respectively, a plan view, a side elevational view and a front view of the bone plate apparatus of FIG. 1;

FIGS. 4A, 4B and 4C show, respectively, a plan view, a side elevational view and a front view of a bone plate apparatus according to another embodiment of the present invention;

FIGS. 5A, 5B and 5C show, respectively, a plan view, a side elevational view and a front view of a bone plate apparatus according to another embodiment of the present invention;

FIG. 6 shows a perspective view of a bone plate apparatus according to an embodiment of the present invention and an insertion tool associated therewith according to an embodiment of the present invention;

FIG. 7 shows a cut-away view of a bone plate apparatus according to an embodiment of the present invention; and

FIG. 8 shows another perspective view of two bone plate apparatus according to embodiments of the present invention.

Among those benefits and improvements that have been disclosed, other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying figures. The figures constitute a part of this specification and include illustrative embodiments of the present invention and illustrate various objects and features thereof.

DETAILED DESCRIPTION OF THE INVENTION

Detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely illustrative of the invention that may be embodied in various forms. In addition, each of the examples given in connection with the various embodiments of the invention are intended to be illustrative, and not restrictive. Further, the figures are not necessarily to scale, some features may be exaggerated to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.

Referring now to FIG. 1 (as well as FIGS. 2A and 2B, showing exploded perspective views of the bone plate apparatus of FIG. 1), one embodiment of a bone plate apparatus according to the present invention is shown. As seen in these Figs., Bone Plate 101 may be attached to bone using Bone Screws 103 a, 103 b and 103 c. In one example (which example is intended to be illustrative and not restrictive), Bone Plate 101 may have a length between 20 mm and 30 mm (e.g., Bone Plate 101 may be provided in a number of distinct lengths). In another example (which example is intended to be illustrative and not restrictive), each of Bone Screws 103 a, 103 b and 103 c may be a self-tapping bone screw. In another example (which example is intended to be illustrative and not restrictive), each of Bone Screws 103 a, 103 b and 103 c may have a diameter selected from the group including (but not limited to) 1.5 mm, 2.0 mm and 2.7 mm. In another example (which example is intended to be illustrative and not restrictive), each of Bone Screws 103 a, 103 b and 103 c may have a length from 4 mm to 8 mm, in 0.1 mm increments.

Further, Locking Plate 105 (which may itself be held in place by Fastener 107 (e.g., a machine screw)) may be used to help prevent screw back-out (FIGS. 2A and 2B show use of Locking Plate 105 and Fastener 107 most clearly).

Further still, Slot 109 (which may have distinct holding positions or detents (as shown in these Figs.), and/or which may not have such detents in order to allow essentially free positioning anywhere within the slot) may be provided to aid in adjustment to an individual patient's anatomy.

Further still, one or more protrusions (or “teeth”) may be provided to aid in maintaining position during and/or after implantation (a number of such teeth are shown but not separately numbered in these Figs.).

Further still, the bottom profile may be streamlined as shown in these Figs. (e.g., in order to reduce the penetration inside the spine).

Referring now to FIGS. 3A, 3B and 3C, a plan view, a side elevational view and a front view of the bone plate apparatus of FIG. 1 are shown. Of note, the dimensions identified in these Figs. are, of course, illustrative and not restrictive.

Referring now to FIGS. 4A, 4B and 4C, a plan view, a side elevational view and a front view of a bone plate apparatus according to an embodiment of the present invention are shown. Of note, these Figs. depict the bone plate apparatus without showing the bone screws. Of further note, the dimensions identified in these Figs. are, of course, illustrative and not restrictive.

Referring now to FIGS. 5A, 5B and 5C, a plan view, a side elevational view and a front view of a bone plate apparatus according to an embodiment of the present invention are shown. Of note, these Figs. depict the bone plate apparatus without showing the bone screws. Of further note, the dimensions identified in these Figs. are, of course, illustrative and not restrictive.

Referring now to one example use of a bone plate apparatus according to the present invention (which example is intended to be illustrative and not restrictive), it is noted that under this example an “open door laminoplasty” (wherein the vertebrae are made to swing open like a door) may be simplified and/or stability may be maintained (such simplification/stability may be obtained by replacing and/or supplementing certain steps and/or components of a conventional laminoplasty with steps and/or components of the present invention (e.g., with an embodiment of the bone plate apparatus described herein). Such an open door laminoplasty is typically performed on a restricted spinal canal in the neck (e.g., a painfully restricted spinal canal), wherein the laminoplasty relieves pressure (e.g., immediately) by creating additional space for the spinal cord and roots.

More particularly, such a laminoplasty is typically performed as follows:

-   -   The surgeon makes an incision on the back of the patient's neck.     -   The surgeon creates a “hinge” by cutting a groove down one side         of the cervical vertebrae.     -   The surgeon cuts all the way through the other side of the         vertebrae.     -   In order to create room for the bones to open like a door, the         surgeon removes the tips of the spinal process.     -   In order to take pressure off the spinal cord and roots, the         surgeon bends open the back of each vertebrae (like a door on         its hinge).     -   The surgeon places, in the opened space of the door,         appropriately sized wedges made of bone.     -   The surgeon allows the door to swing shut. Since the wedges stop         the door from closing all of the way, the spinal cord and roots         receive additional space.

Referring now to FIG. 6, it is seen that Insertion Tool 601 may be used to aid insertion into a patient (e.g., to make placement quick and easy), and that Insertion Tool 601 may include Handle 603, Shaft 605 and Mounting Mechanism 607 (which may be used to hold a bone plate and/or to aid in turning the various screws associated with the bone plate).

Referring now to FIG. 7, a cut-away view of a bone plate apparatus according to an embodiment of the present invention is shown. Of note, this Fig. clearly shows Detents 703 a, 703 b and 703 as well as Machine Screw Retaining Thread 705.

Referring now to FIG. 8, another perspective view of two bone plate apparatus according to embodiments of the present invention are shown.

In another embodiment, some or all of the components may include or be made essentially entirely from a commercially pure material (e.g., Titanium and/or Alloy Titanium).

In another embodiment, Indications relating to use of the present invention may include (but not be limited to):

-   -   For use as laminoplasty plate for cervical spine (from C2-C7)     -   For use as orthognathic plate for fixation (e.g., permanent         fixation) of bone segment(s) after a sagittal split Osteotomy.

While a number of embodiments of the present invention have been described, it is understood that these embodiments are illustrative only, and not restrictive, and that many modifications may become apparent to those of ordinary skill in the art. For example, while the present invention has been described principally with respect to three bone screws, any desired number may, of course, be utilized. Further, the teeth, grooves and/or ridges may be placed at any desired position(s) on the bone plate apparatus. Further still, one or more slots may be utilized for one or more bone screws. Further still, any desired number of detents may be utilized. Further still, the angle between the portion of the bone plate shown principally with one bone screw and the portion of the bone plate shown principally with two bone screws may be any desired angle. Further still, any desired mechanism(s) for locking one or more bone screws relative to the bone plate may be utilized (instead of or in addition to the locking plate described above). Further still, the bone plate apparatus may, of course, have any desired dimensions (e.g., for any desired patient—man, woman or child). Further still, the bone plate apparatus of the present invention may be provided in a “line” or “family” of devices (e.g., small, medium and large; adult, child; male, female). Further still, the bone plate apparatus of the present invention may be provided in standard sizes. Further still, one or more components may be constructed of Ti, cobalt chromium, surgical steel and/or any combination thereof. Further still, a “hole” may be of any desired shape (e.g., circular, square, oval, rectangular, etc.). Further still, any steps relating to manufacture and/or use may be performed in any desired order. 

1. An apparatus placed by an implantation tool for spacing a first section of a divided lamina apart from a second section of the divided lamina following a laminoplasty procedure, comprising: a first portion for attachment to the first section of the divided lamina, wherein the first portion includes at least one hole therethrough for receiving a first fastener driven into the first section of the divided lamina; a second portion for attachment to the second section of the divided lamina, wherein the second portion includes at least one hole therethrough for receiving a second fastener driven into the second section of the divided lamina; an intermediate portion connecting the first and second portions, wherein the intermediate portion connects the first and second portions such that the first and second portions are spaced apart from one another along a first axis and the first and second portions are offset from one another along a second axis which is generally perpendicular to the first axis; a tab portion extending from the intermediate portion from a position between the first portion and the second portion for forming a space for receiving at least part of the first section of the divided lamina; a mechanism for preventing the first fastener from backing-out of the hole into which the first fastener is received; and a recess in a surface of the first portion opposite the tab portion, which recess is configured to be: (a) engagable by the tool for placing the apparatus between the first and second sections of the divided lamina; and (b) engagable by the mechanism for preventing the first fastener from backing-out of the hole into which the first fastener is received.
 2. The apparatus of claim 1, wherein the recess is threaded.
 3. The apparatus of claim 2, wherein the recess has a machine screw thread.
 4. The apparatus of claim 1, wherein the recess extends at least partially into the first portion.
 5. The apparatus of claim 4, wherein the recess extends through the first portion.
 6. The apparatus of claim 2, wherein the tool for placing the apparatus between the first and second sections of the divided lamina includes a mechanism for engaging the threaded recess.
 7. The apparatus of claim 6, wherein the mechanism for engaging the threaded recess comprises a screw.
 8. The apparatus of claim 2, wherein the mechanism for preventing the first fastener from backing-out of the hole into which the first fastener is received comprises a locking plate held in place by a screw engaging the threaded recess.
 9. The apparatus of claim 1, wherein at least one of the first fastener and the second fastener is a bone screw.
 10. The apparatus of claim 9, wherein at least one of the first fastener and the second fastener is a self-tapping bone screw.
 11. The apparatus of claim 1, wherein the first portion includes a plurality of generally circular holes therethrough for receiving a respective plurality of fasteners driven into the first section of the divided lamina.
 12. The apparatus of claim 1, wherein the second portion includes a plurality of generally circular holes therethrough for receiving a respective plurality of fasteners driven into the second section of the divided lamina.
 13. The apparatus of claim 12, wherein the plurality of holes through the second portion are arranged in a generally linear pattern.
 14. The apparatus of claim 1, wherein the hole of the second portion is in the form of a slot.
 15. The apparatus of claim 14, wherein the slot includes at least one detent.
 16. The apparatus of claim 1, wherein the apparatus comprises a material selected from the group including: (a) titanium; and (b) titanium alloy.
 17. The apparatus of claim 1, wherein at least one of a surface of the first portion adjacent the first section of the divided lamina and a surface of the second portion adjacent the second section of the divided lamina is textured.
 18. The apparatus of claim 17, wherein the texture aids in maintaining position of the apparatus relative to at least one of the first section of the divided lamina and the second section of the divided lamina.
 19. The apparatus of claim 18, wherein the texture is selected from the group including: (a) teeth; (b) grooves; and (c) ridges.
 20. The apparatus of claim 1, wherein the tab portion is configured to at least partially support the first section of the divided lamina when the first fastener is driven into the first section of the divided lamina.
 21. The apparatus of claim 1, wherein the first and second portions are disposed generally parallel to one another.
 22. The apparatus of claim 1, wherein the first and second portions are disposed at an angle relative to one another.
 23. A system for spacing a first section of a divided lamina apart from a second section of the divided lamina following a laminoplasty procedure, comprising: (i) a spacer including: (a) a first portion for attachment to the first section of the divided lamina, wherein the first portion includes at least one hole therethrough for receiving a first fastener driven into the first section of the divided lamina; (b) a second portion for attachment to the second section of the divided lamina, wherein the second portion includes at least one hole therethrough for receiving a second fastener driven into the second section of the divided lamina; (c) an intermediate portion connecting the first and second portions, wherein the intermediate portion connects the first and second portions such that the first and second portions are spaced apart from one another along a first axis and the first and second portions are offset from one another along a second axis which is generally perpendicular to the first axis; (d) a tab portion extending from the intermediate portion from a position between the first portion and the second portion for forming a space for receiving at least part of the first section of the divided lamina; (e) a mechanism for preventing the first fastener from backing-out of the hole into which the first fastener is received; and (f) a recess in a surface of the first portion opposite the tab portion; and (ii) an implantation tool, including: (a) a handle; and (b) a mechanism for engaging the recess; wherein the recess is threaded, the mechanism for preventing the first fastener from backing-out of the hole into which the first fastener is received includes a threaded element and the mechanism of the implantation tool for engaging the recess includes a threaded element; and wherein the recess is configured to be: (a) engagable by the threaded element of the implantation tool for placing the spacer between the first and second sections of the divided lamina; and (b) engagable by the threaded element of the mechanism for preventing the first fastener from backing-out of the hole into which the first fastener is received.
 24. A method for spacing a first section of a divided lamina apart from a second section of the divided lamina following a laminoplasty procedure, comprising: (i) providing a spacer including: (a) a first portion for attachment to the first section of the divided lamina, wherein the first portion includes at least one hole therethrough for receiving a first fastener driven into the first section of the divided lamina; (b) a second portion for attachment to the second section of the divided lamina, wherein the second portion includes at least one hole therethrough for receiving a second fastener driven into the second section of the divided lamina; (c) an intermediate portion connecting the first and second portions, wherein the intermediate portion connects the first and second portions such that the first and second portions are spaced apart from one another along a first axis and the first and second portions are offset from one another along a second axis which is generally perpendicular to the first axis; (d) a tab portion extending from the intermediate portion from a position between the first portion and the second portion for forming a space for receiving at least part of the first section of the divided lamina; (e) a mechanism including a threaded element for preventing the first fastener from backing-out of the hole into which the first fastener is received; and (f) a recess in a surface of the first portion opposite the tab portion, wherein the recess is threaded; (ii) providing an implantation tool, including: (a) a handle; and (b) a mechanism including a threaded element for engaging the recess; (iii) threading the threaded element of the implantation tool to the recess; (iv) using the implantation tool to position the spacer adjacent the first and second sections of the divided lamina; (v) driving each of the first and second fasteners into a respective section of the divided lamina; (vi) unthreading the threaded element of the implantation tool from the recess; and (vii) threading the threaded element of the mechanism for preventing the first fastener from backing-out of the hole to the recess.
 25. The method of claim 24, wherein the steps are carried out in the order recited. 